The present teachings are predicated upon providing an improved heater and more preferably an improved heater including sensing capabilities for use in a vehicle. Generally, heaters include a wire that is formed in a pattern. The wire produces heat when electricity is applied to the wire. The wire may also be placed in a carbonaceous material so that as the wire heats up, the heat is diffused into the carbonaceous material heating a larger area. Heaters may include electrodes that are connected by a positive temperature coefficient material so that electricity is conducted from one electrode through the positive temperature coefficient material to the other electrode and heat is produced. Other heaters have a woven configuration where a plurality of long materials are woven together to form a heater. Yet another heater may include positive temperature coefficient material that provides heat as power extends through the positive temperature coefficient material. Each of these heaters are useful in providing heat and each heating type provides certain advantages and may have certain drawbacks.
In addition to heaters, sensors may be installed within a vehicle component. These sensors may be an occupant sensor that determines the presence of an occupant within a vehicle seat, the weight of the occupant, the size of the occupant, or a combination thereof so that an air bag may be turned on or off based upon sensed characteristics. Typically, when a heater and an occupant sensor are used, two discrete components are installed within a component so that one produces heat and the other senses. Having two discrete devices adds to the complexity of the system, increases installation expenses, increases the number of components that may fail, increases packing space, may cause electrical interference between the two devices, or a combination thereof. Therefore, it is desirable to have a combination heater that includes sensing capabilities and heating capabilities so that the heater both heats and senses the presence of an occupant, the position of an occupant, or both without the need for additional devices.
Examples of heaters may be found in U.S. Pat. Nos. 5,824,996; 5,935,474; 6,057,530; 6,150,642; 6,172,344; 6,294,758; 7,053,344; 7,285,748; and 7,838,804; all of which are incorporated by reference herein for all purposes. Examples of combination sensors and heaters may be found in U.S. Pat. Nos. 5,006,421; 6,270,117; 6,392,542; 7,500,536; 7,928,341; 8,400,323; and U.S. Patent Application Publication Nos. 2001/0001522; 2009/0255916; 2010/0277186; 2011/0290775; 2011/0006788; 2011/0148648; 2011/0307148; 2012/0001463; 2012/0161953; 2013/0020305; 2013/0098890; 2013/0113239; 2013/0127211; European Patent No. EP2572929 and International Application No. WO2010/0065411; WO2011/079092; WO2012/038325; WO2012/038326; WO2012/113833; and WO2013/050621 all of which are incorporated by reference herein in their entirety for all purposes.
It would be attractive to have a combination heater and sensor that are free of discrete components. It would be attractive to have a heater that acts as a sensor without the addition of any additional sensing elements. What is needed is a flexible heater that provides good heating performance and also can be used as a sensor so that the heater/sensor may be installed in compact spaces, in spaces that require a high degree of flexibility, or both. It would be attractive to have a combination heater and sensor that heats an occupant and senses if the occupant of a particular space is in contact with the combination heater/sensor.